This invention relates generally to fluid handling a medical environment, and more particularly to a burette top having an air filter that resists blockage better than prior devices.
For years there has been a problem in the medical industry with burette assemblies being tilted so that; the filter paper in the air inlet filter becomes wetted. Once this happens, the filter material, even if hydrophobic, becomes saturated with water or liquid and does not permit air to enter the burette. Without an air vent, a burette assembly will not function.
Some current burette assemblies have a molded top having a cylindrical port on top which accepts and air inlet filter assembly that is press fit onto the port. This arrangement provides filtered air flow to the interior of the burette assembly. Under normal operation, this design is satisfactory, but if the burette is tilted horizontal, for example, while a patient is being transferred, fluid from the burette may wet the filter. Even when the burette is returned to its upright position, fluid may not leave the port, because of surface tension, and the filter will remain blocked, creating negative pressure that prevents the burette system from operating. This can be a serious problem, depending on which part of the body to which the burette is connected. Nurses are trained not to tilt burette assemblies, but accidents are frequent.